If you find that it is not a hairball... I don't know this for sure about animals but I know ppl can vomit feces it means there is a blockage in the digestive system and usually results in having the pice of the intestine removed that is blocked... Is your cat going to the bathrom okay.. I mean Number 2?? If he/she is then it is probably just a hairball...

edit: nevermind I didn't read the last few that said she was fine now...sorry
glad to hear though